Attention 'Bubbling' for New Twist on Old Water Treatment Technology

By Elona Malterre

An innovative update to a century-old water-treatment technology could help clean up oilsands tailings ponds in Alberta, says the company making the system.

Sionix Corporation, based in Santa Monica, California, makes water- and wastewater-treatment systems that use dissolved air flotation (DAF) technology, which has been around for about 100 years. Sionix's treatment units, however, use a patented DAF process that produces extremely small microscopic-sized bubbles to more efficiently remove contaminants from water.

The technology would be "perfect for oilsand tailings ponds," Jim Currier, chairman and CEO of Sionix, told EnviroLine. "Basically . . . we should be able to bring the water discharge (from tailings ponds) to standards which are acceptable under a number of testing protocols," including World Health Organization standards.

Oilsands tailings ponds, which contain salts, heavy metals, hydrocarbons, naphthenic acids and other pollutants that are toxic to birds, fish and other wildlife, cover more than 130 sq km in northern Alberta. While a small portion of the tailings water is recycled and reused in oilsands operations, the rest of it is held in the ponds.

According to Environment Canada's National Pollutant Release Inventory, the volume of lead and arsenic produced by oilsands operations and deposited in tailings ponds increased by 26 per cent during the past four years, the Globe and Mail reported in August 2010.

Currier said that Sionix's (http://www.sionix.com/) treatment units were used to clean up water in a dam in Orange County, California, that was unusable because of contamination by high concentrations of magnesium, iron and organic matter. The treated water is now being pumped back into the municipal water supply, he said.

In October 2010, Sionix installed one of its mobile water treatment systems at Wenning Poultry Farm in Fort Recovery, Ohio, to remove ammonia from chicken manure in an anaerobic digester that produces electrical power.

The farm's digester had been producing about a half-megawatt of electricity, but the goal is to generate about one MW from the waste of approximately one million chickens, Mary Wenning said in an interview.

Compared with cattle manure, "it's a lot harder to transfer chicken manure into power . . . the smaller the animal the more ammonia is concentrated into their manure," she explained. "Chicken manure has a lot of ammonia in it whereas dairy manure has not."

Wenning Poultry Farm also wanted a closed-loop system, with no treatment ponds or other technologies that could potentially cause environmental issues, Wenning said.

A centrifuge in the farm's anaerobic digester wasn't removing sufficient amounts of ammonia from recycled water going back into the digester, she said. "It was not a good living environment for the bacteria," resulting in the microbes not producing enough gas to efficiently fuel the power-generating operation.

"So by putting in a water treatment system that takes the ammonia out and finishes the cleanup that the centrifuge couldn't do, I now have my closed-loop system," Wenning said.

A closed-loop, environmentally friendly system was necessary because the chicken farm is about 1.5 kilometres south of Fort Recovery, and in a direct line to the school, church and football stadium, she said. "You can imagine all the calls we used to get."

Sionix's mobile water treatment system was installed in a 200- by 400-foot manure barn at the farm in October 2010. Apart from a couple of fine tunings, the system is running extremely well, Wenning said.

The system took about five weeks to fabricate, assemble and ship, Sionix said in a news release. Telemetry enables remote access to real time-operating data that Sionix can display on any computer with Internet access and company PDA telephones, to show the system's efficiency.

Jim Matthews, senior vice-president of the environmental water division at Pacific Advanced Civil Engineering (PACE), told EnviroLine that Sionix's system "is way better" in terms of efficiency and is less expensive than "fancier, more expensive" water-purification technologies. PACE, which is Sionix's engineering partner, gets several requests from water remediation companies to do independent studies of products and processes.

Everything required for installing Sionix's mobile system is shipped in one container, which is an advantage for remote oil drilling operations that need to treat water used in hydraulic fracturing operations, Matthews said.

When asked if he would drink water used for fracing after it had been treated with a Sionix unit, Matthews replied: "Yes, I would drink the water out of the fracing stream."

Sionix says it is working with a company in Arkansas to remove impurities from frac water so it can be returned to useable water supplies.

According to the company's literature, the effectiveness of conventional dissolved air flotation technology has been limited to using bubble sizes of 50 microns or larger. The size of the bubbles is important because the smaller the bubble, the greater the surface tension and the more electrical charge. That means smaller bubbles can hold together longer and attach to more contaminants, which are then removed from the water, the company says.

Sionix system's patented air pressure process produces bubbles in the one micron and sub-micron sizes, Currier said. Flocculent is added to wastewater to bring together small sediment particles. The bubbles adhere to organic particles suspended in the water, floating the contaminants to the surface where they are then skimmed off.

The company's technology can remove 99.95 per cent of organic contaminants, Currier said. It also can remove heavy metals and valuable elements, including mercury, copper, lead, arsenic and gold, he added.

Modular units can be built to various water treatment capacities, ranging from mini-units (10,000 to 50,000 gallons per day) through to units handling up to 600,000 gal/day. They are shipped in standard 30- or 40-foot shipping containers that can by carried by truck, train, plane, helicopter or ship.

Sionix's Magna DAF, a stationary unit, can treat 1.2 millions gallons of water per day.

The company has a "pipeline of projects" in the works, including cleaning up acid mine drainage in Canada, South Africa, Siberia and other parts of the world, Currier said. EnviroLine

Elona Malterre

Editor, EnviroLine

THE BUSINESS PUBLICATION FOR THE ENVIRONMENT INDUSTRY

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